/*
 * Copyright (c) 2004-2022, University of Oslo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors 
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.hisp.dhis.common;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.apache.commons.lang3.BooleanUtils;

/**
 * @author Morten Olav Hansen <mortenoh@gmail.com>
 */
public final class PagerUtils {

  public static <T> List<T> pageCollection(Collection<T> col, Pager pager) {
    return pageCollection(col, pager.getOffset(), pager.getPageSize());
  }

  public static <T> List<T> pageCollection(Collection<T> col, int offset, int limit) {
    List<T> objects = new ArrayList<>(col);

    if (offset == 0 && objects.size() <= limit) {
      return objects;
    }

    if (offset >= objects.size()) {
      offset = objects.isEmpty() ? objects.size() : objects.size() - 1;
    }

    if ((offset + limit) > objects.size()) {
      limit = objects.size() - offset;
    }

    return objects.subList(offset, offset + limit);
  }

  public static boolean isSkipPaging(Boolean skipPaging, Boolean paging) {
    if (skipPaging != null) {
      return BooleanUtils.toBoolean(skipPaging);
    } else if (paging != null) {
      return !BooleanUtils.toBoolean(paging);
    }

    return false;
  }

  private PagerUtils() {}
}
